This invention relates to imprinting systems, such as, postage meter mailing machine, which systems are used to imprint information on a sheet-like median and, more particularly, to a postage meter mailing machine utilizing flat bed printing technics and employing a platen assembly.
In the mail processing field, it is most desirable for a system operator to be able to deliver to mail processing equipment a batch of "Mixed mail", that is, the batch is comprised of a large number of envelopes of varying dimensions, particularly thickness, and weight. The ability of a mail processing system to process a large variety of mixed mail eliminated the need of the system operator from performing the preliminary steps of presorting the mail. It is further desirable for mail processing equipment to be able to weigh the individual envelopes and affix the appropriate postage value indicia in accordance with the envelope weight. It is generally considered advantageous if the mail processing equipment can imprint a quality indicia upon envelopes varying in thickness from that of a postcard to approximately a fourth (1/4) of an inch. It is also considered advantageous for the mail processing equipment to possess the capability to imprint a postage indicia on tape strips which can be affixed to packages.
It is known to provide mail processing equipment comprised of a feeder for singularly delivering envelope in series to a transport assembly. The transport assembly deposits the envelope on the scale for weighing. After a sufficient time to assure a true scale reading of the envelope weight, commonly referred to as "weight on the pause", the transport assembly again assumes control over the envelope and delivers the envelope to the a mailing machine.
The mailing machine is most commonly comprised of a integral transport assembly and attached rotatable print drum type postage meter. The mailing machine transport assembly assumes speed control over the envelope performing any necessary speed adjustments to the envelope required to match the envelopes traversing speed with the imprinting speed to the postage meter print drum to promote a quality indicia print. It is known for the postage meter to include a value setting mechanism under the influence of the scale which causes the postage meter value setting mechanism to adjust the postage meter printing mechanism for printing of the appropriate postage rate on the approaching envelope according to the envelope weight as determined by the scale.
The mail processing system depicted above has as its primary objectives (i) the capability to process a dimensionally wide variety of envelopes particularly with respect to thickness and weight (ii) as fast as possible in terms of envelope per second (iii) while applying a quality postal indicia. The described mail processing system has several limiting factors with respect to increasing throughput relative to system cost. One such limiting factor is represented by the time required in transporting the envelopes from one process station to another. Another limiting factor is reflected in the time necessary to obtain an accurate weight from the scale. While such factors as transport time and weighing time can conceivably be decreased by incorporating advance system techniques, the rule of diminishing returns predicts that small improvements in system throughput by such an incorporation would be achievable at disproportional increases in system cost.
In the aforedescribed system, postage meters utilization of flat bed printing technics are seldom employed. That is, such postage meters require the envelope to stationary located in the postage meter in order to imprint the postage indicia. As a result, postage meters utilizing flat bed printing technics in such mail processing equipment would conventionally introduce another interruption to the envelope process procedure and, hence, the preference for postage meters which employ rotary printing techniques.
One possible alternative means of increasing the throughput of such mail processing systems is to provide multiple scales and a suitable transport system such that the scales are placed in alternative use. Such an arrangement would conceivably allow overlapping of system process or function to achieve a significant increase system through. However, such an alternative represents added cost from both an equipment and system complexity standpoint.